Ryan23
09-18-2006, 03:29 PM
So I just rebuilt the Holleys on the Spitfire last weekend. During the previous outing, we had a problem with fuel leaking on the intake after a WOT pull. Looked to be flooding and then pooling in between runners 2/3 and 5/6. A little unnerving to the say the least!
All went well with the rebuild, no hiccups sputters or issues yesterday. The previous carb rebuilder put a secondary metering body gasket in the wrong spot :bonk:. We hauled around the bay anywhere between 4 and 5K yesterday, no more leaks. She'll give me 52.8 mph with the trim in the middle hole using these old school brass props.
Setting the idle mixture was pretty much pointless. Holley tells you to tweak for the highest vacuum reading @ idle. She's a bit lopey, I've only got 12" of vacuum out of both motors, regardless of screw setting (sans turning them all the way in which stalls them). So I'm thinking, "Man, these are probably some agressive 'Marine-unfriendly' cams to give me such little idle vacuum". Let me call owner number three up...
He didn't know specifics but told me a Speedshop (Charlie's) in Evansville, IN rebuilt the motors circa 88'. Apparently they were a pretty well respected oulaw motor shop. According to owner #3, the Speedshop told him that these motors were 400+ HP a piece and could turn 7500 RPM, no sweat. Pretty much useless in this app but whatever. So yeah, they probably have some aggressive cams in them. Aside from pulling a motor, I have no way of knowing what cam is in it. They do wear GM Bowtie heads with some spiffy retainers though :).
On to the "Fact or Fiction"? question, owner #3 contends that he went to these brass props because of problems with the aluminum Volvo props. Purportedly, when he slammed the throttles to the stops, it pulled the pitch out of his Volvo props. Is this feasible or are these clouded memories of a deluded old man? For what it's worth, I do have some new props coming...hopefully we can kick it up a notch or two.
Ryan
All went well with the rebuild, no hiccups sputters or issues yesterday. The previous carb rebuilder put a secondary metering body gasket in the wrong spot :bonk:. We hauled around the bay anywhere between 4 and 5K yesterday, no more leaks. She'll give me 52.8 mph with the trim in the middle hole using these old school brass props.
Setting the idle mixture was pretty much pointless. Holley tells you to tweak for the highest vacuum reading @ idle. She's a bit lopey, I've only got 12" of vacuum out of both motors, regardless of screw setting (sans turning them all the way in which stalls them). So I'm thinking, "Man, these are probably some agressive 'Marine-unfriendly' cams to give me such little idle vacuum". Let me call owner number three up...
He didn't know specifics but told me a Speedshop (Charlie's) in Evansville, IN rebuilt the motors circa 88'. Apparently they were a pretty well respected oulaw motor shop. According to owner #3, the Speedshop told him that these motors were 400+ HP a piece and could turn 7500 RPM, no sweat. Pretty much useless in this app but whatever. So yeah, they probably have some aggressive cams in them. Aside from pulling a motor, I have no way of knowing what cam is in it. They do wear GM Bowtie heads with some spiffy retainers though :).
On to the "Fact or Fiction"? question, owner #3 contends that he went to these brass props because of problems with the aluminum Volvo props. Purportedly, when he slammed the throttles to the stops, it pulled the pitch out of his Volvo props. Is this feasible or are these clouded memories of a deluded old man? For what it's worth, I do have some new props coming...hopefully we can kick it up a notch or two.
Ryan